This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Currently we do not have adequate treatment for approximately one fourth of pediatric patients with epilepsy. Anti-epileptic medications either do not stop the seizures or result in unacceptable side effects. These patients are not candidates for neurosurgical intervention or the intervention has not been successful. More than 70 years ago Ketogenic Therapy was developed for epilepsy. It is based on an adequate intake of protein, minimal intake of carbohydrate, and a very high intake of fat to provide needed calories. The popularity of Ketogenic Therapy has waxed and waned, but the efficacy reported by many investigators is similar to that of anti-epileptic drugs. However there are no consensus guidelines for administration of Ketogenic Therapy and the mechanism of action remains unknown. In an effort to further develop guidelines for administration of Ketogenic Therapy at the University of Florida and to collect baseline data for the design of future intervention trials, we propose a preliminary natural history study with two strata. The first stratum will be Ketogenic Therapy experienced patients and a second will be Ketogenic Therapy na[unreadable]ve patients. Efficacy of Ketogenic Therapy will be measured using data concerning seizures and requirements for anti-epileptic drugs. Data will also be collected concerning potential adverse effects of Ketogenic Therapy including impaired growth and dyslipidemia. Since the role of the caregiver in this labor intensive therapy is critical, an education and training program for caregivers will be refined.